The inventors have observed that there is a clinical need for rapid and accurate diagnosis and treatment of infections. To meet this need, the inventors have observed that it would be useful for clinicians to be able to determine, rapidly and accurately, whether the microorganism causing the infection is sensitive to particular antibiotics, e.g. in order to treat patients appropriately, minimize their suffering and prevent potential complications from inappropriately treated infections, whilst at the same time reducing costs to healthcare organisations and the wider community.
Urinary tract infections (“UTIs”) are a worldwide patient problem, particularly common in female patients, with 1 in 2 women experiencing a UTI at some point in their life1,2. It is predominantly caused by species of Escherichia coli (“E. coli”) Millions of patients seek medical care in relation to UTIs every year, accounting for 1-3% of GP consultations in the UK every year3.
Current methods of identifying the specific bacterium causing a UTI are very time-consuming. Typically, once a urine sample is provided by a patient, this sample is examined microscopically and cultured for 24 to 48 hours in the laboratory in order to identify the offending pathogenic organism(s). If an organism is identified, it usually takes the same amount of time to test the organism for its sensitivity to different antibiotics3. Because of this delay, initial treatment for UTIs is nowadays usually provided by clinicians on the basis of patient symptoms and/or a positive urine dipstick result and empirical treatment is prescribed using a broad spectrum antibiotic based on the presumed causative agent, most commonly E. coli4-7. This practice may lead to over-treatment (treatment given when no UTI is present), under-treatment (UTI not treated initially), or inappropriate treatment (ineffective antibiotic given). In addition, over the last two decades the emergence of antibiotic resistant strains of E. coli (up to 1 in 5 cases, and this is expected to rise) has made correct and fast diagnosis of UTI with rapid identification of the causative agent and its antibiotic sensitivities, of paramount importance8-10.
The same issues of lengthy diagnosis and inappropriate treatment apply to conditions other than UTI, such as meningitis, pneumonia, sepsis and other infectious diseases.
The present invention has been devised in light of the above considerations.